SPM Technologies: Past, Present and Future Qing Tu, MSE & NU - - PowerPoint PPT Presentation

SPM Technologies: Past, Present and Future

Qing Tu, MSE & NUANCE Center

Outline

– Overview of AFM history – Basic Modes – Advanced Modes

A Revolution in the Nanoworld: Scanning Tunnelling Microscope

A Brief Moment in the History of STM

Oberlech July 1985 A Giant Step for Nanoscience and Technology

Miedema, Baratoff, Quate, Salvan, Feenstra, Kaiser, Welland, Hoesler, Berghaus, Baro, Marti, Vieira, Stoll, Dürig, Muralt, Behm, Hansma, Celotta Garcia, Neddermeyer, Van Kempen, Ringger, Pohl, Abraham, Chiang, Demuth, Humbert, Gimzewski, Salemink, Lang, Golovchenko, Güntherodt, Miranda, Fink, Gomez Büttiker, Pethica, Baldeschwieler, Rohrer, Wilson, Elrod, Müller, Binnig, Gerber Middle row: Front row: Back row:

You are familiar with needlepoint. By placing small stitches on a surface, you can make designs.

0.07 nm

This stick figure is made by placing carbon monoxide molecules onto a surface using a Scanning Tunneling

• Microscope. Each piece was made

with a carbon monoxide molecule, with atoms only 0.07 nanometers across. The “drawing” seems childish until you realize how small the carbon dioxide molecules are.

Science Museum London „The Making of the Modern World“ Original AFM

B A C D

AFM UNIVERSE

Atomic Force Microscope

a. Nonconducting Surface – No bias voltage. b. Sensing tip is cantilever force sensor. c. Relies on “van der Waals” forces between atoms and molecules

• Instead of using light or

electrons to probe the sample, the AFM uses a tip suspended above the surface.

• The attractions or repulsions

between the tip and the surface cause the tip to deflect.

• A laser senses the deflection.
• Scanning the tip across the

surface generates the image.

a. Nonconducting Surface – No bias voltage. b. Sensing tip is cantilever force sensor. c. Relies on “van der Waals” forces between atoms and molecules

Deflection ~ Force

Piezoelectric translators

Tip angstroms from surface (repelled) Constant force Highest resolution May damage surface contact mode non-contact mode Tip hundreds of angstroms from surface (attracted) Variable force measured Lowest resolution Non-destructive tapping mode Intermittent tip contact Variable force measured Improved resolution Non-destructive

• High bandwidth enables exceptional force control and high scan rates with closed-loop

accuracy to surpass efficiency of any other commercial AFM system

• 20Hz Tapping Mode scan rates provide excellent quality images, matching that typically

seen at 1Hz and maintaining good quality even at scan rates >100Hz

• Higher speed ScanAsyst delivers superb quality images at 6Hz and a surveying capability

up to a 32Hz scan rate

ADVANCES in SPM: Quantitative Nanomechanics

Height 100 nm Deformation 25 nm Adhesion 5 nN Modulus 10 MPa

Deformati

• n

ADVANCES in SPM: Quantitative Nanomechanics

• 2D Ruddlesdon-Popper HOIPs:(CmH2m+1NH3)2(CH3NH3)n-1PbnI3n+1

Here m = 4, n = 3

Tu et al., ACS Nano, 2018, 12(10), 10347 – 10354

ADVANCES in SPM: Quantitative Nanomechanics

Tu et al., ACS Nano, 2018, 12(10), 10347 – 10354

𝑮 = 𝝉𝟏

𝟑𝑬𝝆𝜺 + 𝑭𝟑𝑬 𝒓𝟒𝜺𝟒

𝒔𝟑

𝝉𝒏 = 𝟐 𝒊 𝑮𝒏𝒃𝒚𝑭𝟑𝑬 𝟓𝝆𝒔𝒖𝒋𝒒

ADVANCES in SPM: Quantitative Nanomechanics

Tu et al., ACS Nano, 2018, 12(10), 10347 – 10354

C4n1

5

– Measure OPV conductivity under illumination – Unravel conduction mechanisms – Combine with PeakForce TUNA & 1ppm environmental control

Photoconductive AFM

Life Science Imaging System

Endothelial Live Lung Cell Nanomechanics

AFM deflection images of live EC prior to any simulation (A); in response to 54 min after treatment with 20 mM imatinib (B) followed by 36 min treatment with 1 mM S1P (C). The mechanical measurements were carried out by acquiring arrays of 32 × 32 loading-unloading curves in the force-volume map.. The time-lapse elastic modulus maps prior to any simulation (D); in response to 54 min after treatment with 20 mM imatinib (E); followed by 36 min after treatment with 1 mM S1P (F). Each pixel indicates the localized sub- cellular elastic modulus.

Nature Scientific Report 5, 11097 (2015) Nature Scientific Report 8 (1) 1002 (2018), Nature Scientific Report 7, 14152 (2017) Nature Materials 15(4), 469 (2016)

Super resonant Ultrasonic vibration: f >>fo AFM tip+cantilever Elastic contact AFM tip+cantilever Noncontact Super resonant Ultrasonic vibration: f >>fo Elastic contact

Ultrasonic Force Microscopy

sample piezo

Trench CS Epoxy Quadrant PD SPM tip

wS

• 1. Introduce ultrasonic (RF) vibration to

sample in contact AFM

• 2. Cantilever essentially rigid (inertially

damped): fsample>> fcantilever

• 3. Ultrasonic cantilever oscillation

amplitude proportional to sample elasticity

ForceF(h) Indentation(h) D F1

Da1

D F2

Da2

Note structure within polymer trench wall Width of high modulus region ~ 120 nm

AFM UFM

Elastic Mapping (Depth)

Science 310, 89 (2005), Nature Nanotechnology 3,501 (2008)

Scanning Near Field Ultrasound Holography (SNFUH): Seeing the Invisible!

Near-Field SPM Platform: ➔ Excellent Lateral Resolution Ultrasound source: ➔ Non-destructive and Depth-Sensitive Holography Paradigm: ➔ Sensitive to “Phase” Perturbations

Direct Application in Failure Analysis

SiN+ Polymer Polymer

Buried internal voids

AFM NFAH

Buried internal voids

SNFUH AFM

X Y

SiN+ Polymer Polymer

Buried internal voids

AFM NFAH

Buried internal voids

SNFUH AFM

X Y

(B) (C)

SiN+ Polymer Polymer

Buried internal voids

AFM NFAH

Buried internal voids

SNFUH AFM

X Y

SiN+ Polymer Polymer

Buried internal voids

AFM NFAH

Buried internal voids

SNFUH AFM

X Y

50 nm 50 nm 50 nm

Polymer

Silicon Nitride

SOD 1µm 500 nm 50 nm

• Scanning Near Field Ultrasound

Holography in Semiconductors – Nanoscale Imaging of embedded features/defects – Quantitative modulus imaging

• f metal-low K dielectrics

– Non-invasive monitoring of molecular markers – Nanoscale non-invasive 3D tomography – Failure analysis and 3D Interconnects – Voiding, delamination with nanometer scale resolution

Science 310, 89 (2005)

Ultrasound Bioprobe for Nanomechanical Analysis

Science Advances 2017; 3:e1701176 Science Advances 2017; 3:e1701176

a b d c Ultrasound Phase AFM Tapping Phase

Magnetic Core Silica Shell Receptor Coating Magnetic Core Silica Shell Receptor Coating Science Advances 2017: 3;e1701176, Nature Scientific Report 8 (1) 1002 (2018), Nature Scientific Report 7, 14152 (2017) Imaging magnetic core nanostructure embedded in refractory silica core shell based molecular marker

a b AFM Ultrasound Phase

fs=2.20 MHz, 4.8 Vpp fc=2.30 MHz, 4.6 Vpp

Intracellular Fibers Decreased Intracellular Gaps Increased Stiffness of Nucleus

Nucleus Region

Ultrasound Bioprobe for Nanomechanical Analysis

AFM topographical image EC cells altered by addition of thrombin and ultrasound bioprobe phase image demonstrates remarkable contrast from intra- cellular fibers. Intracellular fibers are predominantly seen in the ultrasound phase image along with stretched gaps and sub-cellular phase contrast on the nuclei region of the cells.

Science Advances 2017: 3;e1701176

S i

Metal 1 SiO2 Metal 2 Thermocouple Junction Thermal Insulating Layer (SiO2) Metal 1 Nano-Rod

Scanning Thermal Imaging System

(Joint Development with APPNANO)

Surface temperature mapping of a silicon micro heater. Left panel: schematic of the silicon micro-heater showing different degrees of ion implanted areas. Gray is plain silicon, blue is low dose implant and pink is high dose implant overlying plain silicon and low dose areas. Middle panel: topography and Right panel: Temp image. The temperature image captures the point- to-point variations in the surface temperature due to joule heating at the center and diffusion

• f

heat by the underlying silicon.

ACS Nano, 2018, 12 (2), pp 1760–1767

In conventional thermocouples, junction is directly in contact with the sample. The the size of the junction determines the resolution. In this current innovative design

• f

the Thermal Probe the resolution is determined by the diameter of the metal -1 nano-rod and not by the size of the junction. Using modern microfacbrication techniques, one can easily create nano-rods of less than 20nm diameter. The smaller size, however, may have impact on the response time of the probe. The nanorod is positioned at the apex of the tip. This brings the nanorod in direct contact with the sample and as a result the thermal sensitivity of the probes is significantly improved. The extended length of the nanorod ( length beyond the thermal junction) helps achieving long

• perational life of the probes.

Topography b Thermal c Thermal Profile d a

a) Schematic illustration of thermal probe interaction with gold nanoparticles (GNP) encapsulated in silica shell. b) Shows AFM topography image and (c) shows a remarkable thermal contrast from embedded GNP in silica. It clearly reveals a high thermal sensitivity, lateral resolution and contrast. The thermal image showing the difference in heat transfer from the tip to the silica shell and silicon substrate. d) Shows the cross-sectional profile where temperature change (∆T) from 0.8-0.9°C was recorded across the particle

Sub-Surface Thermal Contrast

ACS Nano, 2018, 12 (2), pp 1760–1767

(a) Optical and (b) AFM images obtained from a MoS2-WS2 heterostructure. (c) Raman spectra obtained from MoS2 and WS2 regions. (d) Raman map of the MoS2-WS2 heterostructure device. (e) AFM topography image of the same device. (f-h) Temperature rise profiles of the device at different dissipated electrical power at VG = +60V. The heating predominantly takes place on the WS2-metal vertical junction and the lateral interface does not contribute to localization of the heat. The green arrows in (h) shows the position of the formed hot-spots. (i) Temperature line profiles on the dashed red line in (h) at different applied powers.

Adcanced Materials (Under Review)

Mapping Hot Spots in Layered Materials

Courtesy: Chad Mirkin

Soft Nanopatterning

11 Million Polymer Pen Array

iv iv

10 μm

Average Feature Size = 42 nm

5 μm Courtesy: Chad Mirkin

Piezoresponse Force Microscopy

• Piezoelectric Materials
• Piezoresponse Force Microscopy

Nano IR System Integrated with AFM and sSNOM (Coming soon!)

Chemical Analysis at nanoscale resolution

Cantilever oscillation ~ IR absorption coefficient

Aperture based Aperture- less Tip localizes the field

Scattering near field optical microscope (sSNOM). This aperture-less system collects scattered energy form the near field resulting in sub-20 nm resolution. In comparison, aperture based traditional NSOM system resolution is limited to 100-150 nm.

• 10’s of nanometer optical

and sub-eV spectral resolution

• Near-field

spectroscopy (nano-FTIR)

• High

speed

• ptical

near- field imaging

• Simultaneous
• ptical

amplitude (reflection) and phase (absorption) measurements

• VIS-IR-THz spectral range.